Combination locks are useful in providing security for possessions. As better combination locks are constructed, surreptitious entry into the safe or other thing protected by the lock becomes more difficult. In many uses of combination locks, the sole importance attached to the lock is its ability to withstand typical attempts at surreptitious entry. However, many safes are entered by one who has seen the owner of a safe dial the combination. This is an especially important problem with respect to safes that are in plain view to persons not having the safe combination.
Such a person does not have to see the entire combination dialed at one time; he can learn one number each time he is able to look at the dial when the combination is being dialed. It may be easy to do this over a relatively short period of time without arousing suspicion of the person opening the safe.
In other applications, however, the combination dial is only visible to those having knowledge of the combination. For example, many one-person businesses have safes out of view of customers. No employees are around to glance at the owner while he is dialing the combination.
Viewing devices or materials have been proposed through which the owner of the safe can view the dial and the numbers thereon when dialing the combination but which prevent one not in a particular location to view the dial, and the present invention utilizes such material.
One object of the present invention is to disclose and provide a combination lock which has interchangeable members to provide for either unrestrictive viewing of the dial or to provide for restricted viewing of the dial depending on the safe owner's desires. A further object of the present invention is to disclose and provide a device which can be easily fit over the dial to allow only limited viewing of the dial.
The material that restricts viewing of the dial must be securely held in place. In the present invention, it is held in a window in a housing in front of the dial. If the view-restricting material is easily removed from the window, those authorized to open the safe may not notice the lack of the material, and the thief may learn of the combination before the material loss is discovered. Therefore, another object of the present invention is to disclose and provide a secure support for the vision-restricting material.
The meeting of these objects will be shown in the specification herein, and other objects, which will become evident in the specification, will also be met.